Hello, I played a bit with your input. Maybe it would be of help.

First I added one person (Jim Morris) to have three levels in your data:

my $input = {
    'Sally Smith'   => { parents => ['Bob Smith',    'Rhonda Smith']},
    'Betty Freeman' => { parents => ['Earl Freeman', 'Harmony Ellis']}
+,
    'Betty Boop'    => { parents => ['Rhonda Smith', 'Louis McFern']},
    'Jim Morris'    => { parents => ['Betty Boop',   'John Wayne']},
};
[download]

You wrote that you want to descent from top, so I made new structure with children relationships and listing all people:

my $people = {};
for my $m (keys %$input) {
    add_person($people,$m, parents => $input->{$m}{parents});
    for my $p (@{ $input->{$m}{parents} }) {
        add_person($people,$p,children => $m);
    }
}

sub add_person {
    my ($people,$name,%params) = @_;
    
    if(! defined $people->{$name}) {
        $people->{$name} = { children => [], parents  => [] };
    }
    for my $par (keys %params) {
        push @{ $people->{$name}{$par} }, 
            ref($params{$par}) eq "ARRAY" ? @{$params{$par}} : $params
+{$par};
    }
}
[download]

The $people structure dumped:

{
  "Betty Boop"    => { children => ["Jim Morris"], parents  => ["Rhond
+a Smith", "Louis McFern"], },
  "Betty Freeman" => { children => [], parents => ["Earl Freeman", "Ha
+rmony Ellis"] },
  "Bob Smith"     => { children => ["Sally Smith"], parents => [] },
  "Earl Freeman"  => { children => ["Betty Freeman"], parents => [] },
  "Harmony Ellis" => { children => ["Betty Freeman"], parents => [] },
  "Jim Morris"    => { children => [], parents => ["Betty Boop", "John
+ Wayne"] },
  "John Wayne"    => { children => ["Jim Morris"], parents => [] },
  "Louis McFern"  => { children => ["Betty Boop"], parents => [] },
  "Rhonda Smith"  => { children => ["Sally Smith", "Betty Boop"], pare
+nts => [] },
  "Sally Smith"   => { children => [], parents => ["Bob Smith", "Rhond
+a Smith"] },
}
[download]

Now you can start with people not having any parents and recurse over children.

for my $top_level (sort keys %$people) {
    next if @{ $people->{$top_level}{parents} };
    print_level($people,$top_level,0);
}

sub print_level {
    my ($people,$name,$level) = @_;
    print "  "x$level,$name,"\n";
    for my $child (@{ $people->{$name}{children} }) {
        print_level($people,$child,$level+1);
    }
}
[download]

It produces this tree using indentation:

Bob Smith
  Sally Smith
Earl Freeman
  Betty Freeman
Harmony Ellis
  Betty Freeman
John Wayne
  Jim Morris
Louis McFern
  Betty Boop
    Jim Morris
Rhonda Smith
  Sally Smith
  Betty Boop
    Jim Morris
[download]

Is this what you expected to see? If yes, producing some kind of javascript tree should be quite easy.

-- Roman